Potentilla supina L. ssp. paradoxa (Nutt.)
Family - Rosaceae
Stem - Spreading to ascending, branched, pubescent with long, spreading hairs.
Leaf - 3-15 cm long, petiolate, stipulate, hairy, compound with 5-7 leaflets. Leaflets 1-3 cm long, +/- elliptic, coarsely toothed.
Inflorescence - Terminal panicles or racemes.
Calyx and bractlets.
Flower - Bractlets 5, 2-5 mm long, sparsely hairy, spreading. Sepals 5, 3-6 mm long, alternating with bractlets, appressed in fruit. Petals 5, 2.5-4.0 mm long, bright yellow, alternating with sepals. Stamens 20.
Fruit - 0.7-1.3 mm long, smooth or somewhat wrinkled, brown, with a corky, winglike appendage along the inner margin.
Flowering - May - September.
Habitat - Streambanks, lake margins.
Origin - Native to North America.
Other info. - This is one of the less common Missouri cinquefoils. It has been found exclusively
in counties bordering the Missouri and Mississippi Rivers, and is probably waiflike, springing up sporadically from seed deposited by
flooding events. This species is easily differentiated from the other Missouri species of Potentilla by its pinnately compound
leaves bearing five or more leaflets.
Photographs taken at Klondike County Park boat ramp, St. Charles, MO, 5-15-2014 (SRTurner).